The PCJR0303 is the optional inner panel for the smallest box in the PCJ Series of Type 4X polycarbonate junction boxes. Its long description reads "Panel 3.6 x 3.6 Fits 4x4 Steel/White", and the series ordering table pairs it with the 4 x 4 in enclosures PCJ443 (solid cover, feet) and PCJ443CC (clear cover, feet), which measure 3.95 in H x 3.95 in W x 3.31 in D (100 x 100 x 84 mm).

The panel gives OEM builders and electricians a flat mounting surface for small terminals, relays or other components inside the enclosure, rather than drilling into the polycarbonate back wall. PCJ enclosures include threaded brass inserts for optional inner panel or terminal kit mounting, with mounting hardware included with the enclosure.

Per the ordering table the PCJR0303 measures 3.56 in H x 3.56 in W (90 x 90 mm). The part drawing shows a 0.07 in thickness and four 0.25 in diameter mounting holes on a 3.00 x 3.00 in pattern. The material is steel with a white finish; the series notes that inner panels are offered in white powder coated finished steel, as well as unfinished aluminum or fiberglass alternatives.

The PCJR0303 ships in a bag at a shipping weight of 1 lb (0.45 kg) and is RoHS and REACH compliant. Identifiers are UPC 623980285191 and UNSPSC 39121324.